Beschrijving:The aircraft was on a flight from Chengdu to Wenzhou and was approaching Wenzhou when, at 1000 m, the flaps were extended. At that moment, the aircraft suddenly pitched down and dove into the ground out of control. The Tupolev crashed into a farm field and exploded, causing a 200x100 feet hole in the ground. Several farmers were injured by the flying debris.

Probable Cause:

PROBABLE CAUSE: A self-locking nut, other than castle nut with cotter pin as specified, had been installed at the bolt for connection between pull rod and bellcranck in the elevator control system. The nut screwed off, resulting in bolt loss, which led to the loss of pitch control.

This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.